A laterally displaceable railway wagon

ABSTRACT

A railway wagon comprising a load carrier, and front and rear bogies, wherein each bogie comprises a platform, which is rotatably mounted. The load carrier is releasably connected to, and laterally displaceable in relation to, the platforms. The load carrier has a front end and a rear end and is provided, at each end, with a connection portion, and two support devices, which are laterally spaced, and which support the load carrier in a position where it is laterally displaced in relation to the platform. The support devices are vertically operable between an idle position and a support position, in which the support devices abut against the ground. Further, the railway wagon comprises a displacement device for laterally displacing the load carrier.

FIELD OF THE INVENTION

The present invention relates to a laterally displaceable railway wagon,which has a load carrier, and front and rear bogies, wherein each bogiecomprises a platform rotatably mounted on the bogie. The load carrier isreleasably connected to the respective platforms, and laterallydisplaceable in relation to the respective platforms.

BACKGROUND OF THE INVENTION

It is an environmental benefit to transport vehicles by train. In orderto facilitate such transport laterally displaceable railway wagons havebeen developed. A laterally displaceable railway wagon is a railwaywagon that can be laterally displaced by swinging out one end thereof,or more particularly one end of a load carrier that is a part of thewhole wagon, such that the vehicle can be driven on board the wagon.Alternatively, the wagon, or a load carrier thereof, is moved inparallel, or it is rotated about a centre seat. Then the wagon isreturned to its original position and the train may depart.

WO 2006/031178 discloses a displaceable railway wagon which in largeworks well. However, the displacement arrangements involve atilt-preventing device, which comprises a crossbar extending across theend of the load carrier. When the end of the load carrier has beendisplaced the crossbar is disconnected at one end thereof and pivotedaway to a position where it does not prevent the loading/unloading rampfrom being lowered or a vehicle from entering or leaving the loadcarrier. The crossbar is inconvenient.

SUMMARY OF THE INVENTION

It would be advantageous to provide a load carrier with a moreconvenient displacement arrangement.

To better address this concern, in a first aspect of the invention thereis presented a railway wagon comprising a load carrier, and front andrear bogies, wherein each bogie comprises a platform, which is rotatablymounted, wherein the load carrier is releasably connected to therespective platforms, and laterally displaceable in relation to therespective platforms. The load carrier has a front end and a rear endand is provided, at each end, with a connection portion, and two supportdevices, which are laterally spaced, and which support the load carrierin a position where it is laterally displaced in relation to theplatform. The support devices are vertically operable between an idleposition and a support position, in which the support devices abutagainst the ground. The railway wagon further comprises a displacementdevice for laterally displacing the load carrier, wherein thedisplacement device comprises a reciprocating launch device, which isarranged to reciprocate laterally of the platform, a launch deviceconnection mechanism for releasably connecting the connection portionwith the launch device, and a platform connection mechanism arranged forreleasably connecting the connection portion with the platform. By meansof the combination of the launch device and the connection mechanisms asmooth displacement of the load carrier is provided.

In accordance with an embodiment of the railway the launch device iselongated and extends laterally of the platform, wherein thedisplacement device further comprises a reciprocating feeding deviceattached to the launch device and to the platform, wherein the launchdevice is movable, by means of the feeding device, between an idleposition, and a laterally displaced position. Thereby the reciprocatingmovement of the launch device is effectively executed. It is possible toobtain a good lateral reach with a space saving device.

In accordance with an embodiment of the railway wagon the feeding deviceis a cylinder assembly.

In accordance with an embodiment of the railway wagon the launch deviceconnection mechanism comprises a reciprocating engagement elementarranged at the connection portion, and a reception portion at thelaunch device, wherein the engagement element is reciprocatingly movableto respectively engage with and disengage from the reception portion.This embodiment provides for a simple yet reliable launch deviceconnection mechanism.

In accordance with an embodiment of the railway wagon, the receptionportion comprises several reception members distributed along the lengthof the launch device. Thereby, several strokes are possible and thelength of the stroke can be rather short, simplifying the construction.

In accordance with an embodiment of the railway wagon the engagementelement is a cylinder assembly, and each reception member comprises anaperture arranged to receive a piston of the cylinder assembly.

In accordance with an embodiment of the railway wagon, the platformconnection mechanism comprises an engagement assembly arranged at theconnection portion, and a seat arranged at the platform and adapted toreceive a piston comprised in the engagement assembly to connect theload carrier with the platform.

In accordance with an embodiment of the railway wagon, the platformcomprises a support surface, which supports the launch device.

In accordance with an embodiment of the railway wagon, the platformcomprises an elongated guide member extending laterally of the bogie,and the launch device comprises a guide beam extending along the lengthof the launch device and slidably engaging with the guide member of theplatform, wherein the guide member and the guide beam are arc shaped. Asunderstood by the person skilled in the art, the lateral displacement ismostly not completely straight, but the end of the load carrier movesalong a radius corresponding to the whole length or half the length ofthe load carrier. However, the radius is large and in any case themovement can still be defined as lateral since the load carrier changesits lateral position.

In accordance with an embodiment of the railway wagon, the load carriercomprises opposite side beams, wherein each side beam comprises aprotruding end portion at each end thereof, and wherein the connectionportion comprises the protruding end portions of the side beams. Inother words, each connection portion comprises two end portions, i.e.the end portions of the opposite side beams at one end of the loadcarrier.

In accordance with an embodiment of the railway wagon the launch deviceis provided with a laterally elongated top surface portion, and eachprotruding end portion is provided with a roller arranged to roll on topof the top surface portion.

In accordance with an embodiment of the railway wagon, the launch devicecomprises a retaining lip extending along a side edge of the launchdevice, and wherein each protruding end portion comprises a retainingmember protruding under the retaining lip overlapping a portion of itsbottom surface. This arrangement reduces a risk of the launch device andthe connection portion to be displaced relative to each other in thelongitudinal direction of the railway wagon such that an offset anglearises. Such an offset angle would complicate the lateral movement ofthe load carrier.

According to another aspect of the invention there is provided a methodof laterally displacing the load carrier. The method comprises:

displacing at least one of the ends of the load carrier by performing atleast one reciprocating movement, comprising a feed stroke and a returnstroke, with the displacement device, until that end of the load carrierhas been moved to a loading/unloading position beside the bogie,comprising:

connecting the connection portion, if disconnected, with the launchdevice;

disconnecting, if connected, the connection portion from the platform;

performing a feed stroke by moving the launch device laterally from anidle position to a laterally displaced position;

lowering a first support device of said support devices to the supportposition;

disconnecting the connection portion from the launch device;

performing a return stroke moving the launch device back to its idleposition;

connecting the connection portion with the launch device and performinganother feed stroke; and

lowering the second support device to the support position.

The method provides solutions to problems and advantages correspondingto those of the railway wagon described above.

In accordance with an embodiment of the method it comprises—applying themethod of claim 15 for simultaneously displacing both ends of the loadcarrier;

disconnecting connections, tubes and cables at both ends of the loadcarrier from the bogies;

removing the load carrier and providing a replacement load carrier; and

assembling the replacement load carrier with the bogies by reversing theabove operations of applying the method of claim 15 and disconnectingconnections, tubes and cables.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail and with reference tothe appended drawings in which:

FIGS. 1 to 4 schematically illustrate launching of a load carrier of anembodiment of a railway wagon according to the present invention; and

FIGS. 5 to 8 are schematic perspective views of a part of the railwaywagon of FIG. 1.

DESCRIPTION OF EMBODIMENTS

The invention concerns a railway wagon which is designed for the modernconcept of loading and unloading of entire vehicles. FIGS. 1 to 4 show aloading process during which a launching operation takes place as willbe described in detail below. The railway wagon 1 comprises a loadcarrier 2, front and rear bogies 3, 4, releasably connected with theload carrier 2. More particularly, each bogie comprises a rotatableplatform 5, 6, thereby constituting front and rear platforms 5, 6, andthe load carrier 2 is releasably connected to the front and rearplatforms 5, 6 at respective front and rear ends 7, 8 thereof. It shouldbe noted that the railway wagon 1 can be pulled in any direction, i.e.with any one of its ends as the front end. The terms front and rear areonly used to identify the two ends in order to facilitate thisdescription of the railway wagon 1. When loading of a vehicle 9, forinstance a truck, is to occur, the rear end 8 of the load carrier 2 isreleased and launched, i.e. laterally displaced, relative to the rearbogie 4 and the rear platform 6. In this case, the load carrier 2 ispivoted on a pivot which is positioned at its front end 7, i.e. therotatable attachment (not shown per se) of the front platform 5 to thefront bogie 3. When the load carrier 2 has been fully launched the truck9 is driven onto the load carrier 2, and the reversed movement of theload carrier 2 is performed back to the original drive position wherethe rear end 8 of the load carrier 2 has been fully reconnected with therear platform 6, and the railway wagon 1 can be pulled away towards thedestination of the truck. When the destination has been reached thefront end 7 is launched, and the truck 9 can drive off and continue toits final destination.

The load carrier 2 comprises two spaced-apart opposite side beams 17,18, providing side walls of the load carrier 2, and a platform part 19,providing a floor of the load carrier 2, extending between the sidebeams 17, 18. Furthermore, the load carrier 2 comprises a ramp 20, 21 ateach end 7, 8 of the load carrier 2. The ramp 20, 21 is used forloading/unloading the load carrier 2, i.e. driving a vehicle on or offthe platform part 19.

More particularly, the load carrier 2 is provided, at the front and rearends 7, 8 thereof, with opposite protruding first and second endportions 11, 12, 13, 14 of the side beams 17, 18. At each end 7, 8 ofthe load carrier 2, the two end portions 11, 12 and 13, 14,respectively, are comprised in a connection portion 15, 16 of the loadcarrier 2. The connection portion 15, 16, and thus the end portions11-14, is releasably connected with the respective front and rearplatforms 5, 6. The load carrier 2 further comprises two support devices30, 31 at each end thereof. Each support device 30, 31 is arranged tosupport the load carrier 2 when it is displaced relative to the platform5, 6. The support device 30, 31 is vertically operable between an idleposition, where it is in an upper most position, and a support position,where it has been lowered into abutment against the ground. It should benoted that the support devices 30, 31 are most schematically shown, formere illustrative purposes, as well as many other parts of the railwaywagon, which are not central for the present invention.

Referring now in particular to FIGS. 5 to 8, the railway wagon 1 furthercomprises, at each end thereof, a displacement device 22 for displacingthe load carrier 2. The displacement device 22 comprises a reciprocatinglaunch device 23 arranged at the platform 6. The launch device 23 isarranged to reciprocate laterally of the platform 6, and thus laterallyof the railway wagon 1. The displacement device 22 further comprises alaunch device connection mechanism 24 arranged at the connection portion16, and more particularly one launch device connection mechanism 24 isprovided at each end portion 13, for releasably connecting the endportion 13 with the launch device 23. It should be noted that preferablythe connection portion 16 of the side beams 17, 18 is provided with acover plate 51 closing the space in which, for instance, a part of thelaunch device connection mechanism is provided. The cover plate can beseen in FIGS. 1-4.

The displacement device 22 further comprises a platform connectionmechanism 25 arranged at the connection portion 16, and moreparticularly one platform connection mechanism 25 is provided at eachend portion 13, for releasably connecting the end portion 13 with theplatform 6. Each platform connection mechanism 25 comprises anengagement assembly 26 attached to the connection portion 16, alaterally extending shelf, or lip, 49 of the platform 6 provided withseats 27, and an anvil portion 52, extending beneath the engagementassembly 26. The shelf 49 is elongated and has a longitudinal extension,i.e. length, in the lateral direction of the railway wagon 1, and alateral extension, i.e. width, in the longitudinal direction of therailway wagon 1. The engagement assembly 26 comprises a motor 34 with arotating drive shaft 34a, and a piston 35, in threaded engagement withthe drive shaft 34a, and reciprocatingly driven by the motor 34 via thedrive shaft 34a. The seats 27 are adapted to receive an end of thepiston 35 to connect the load carrier 2 with the platform 6. In otherwords, an engagement is obtained between the connection portion 16 andthe platform 6, and more particularly the shelf 49 of the platform 6.The engagement is activated by driving down the piston 35 to engage withone of the seats 27 and push the shelf 49 against the anvil portion 52.Thus, when the platform connection mechanism 25 is in a locked state,the shelf 49 is clamped between the piston 35 and the anvil portion 52.

The launch device 23 is elongated and extends laterally of the platform6. The displacement device 22 further comprises a reciprocating feedingdevice 29 attached to the launch device 23 and to the platform 6,wherein the launch device 23 is movable, by means of the feeding device29, between an idle position, and a laterally displaced position. In theidle position, the launch device 23 is resting within the width of theside beams 17, 18. In the laterally displaced position, the launchdevice 23 protrudes beyond that width at one side or the other of therailway wagon 1. That is, the launch device 23, and thus the loadcarrier 2, can be laterally displaced to both sides. The feeding device23 is, for instance, a cylinder assembly.

The launch device connection mechanism 24 comprises a reciprocatingengagement element 28, arranged at the connection portion 16, and moreparticularly one engagement element 28 is arranged at each end portion12, and a reception portion 32 at the launch device 23. The engagementelement 28 is movable to respectively engage with and disengage from thereception portion 32 of the launch device 23. The reception portion 32comprises several reception members 33 distributed along the length ofthe launch device 23. The engagement element 28 is a cylinder assemblycomprising a cylinder 36 and a piston 37, and each reception member 33comprises an aperture 38 arranged to receive the piston 37.

The platform 6 comprises a support surface 39 which supports the launchdevice 23, such that the launch device slides on the support surface 39.Other alternatives are of course feasible, such as a suitable kind ofroller bearings, however the forces are high so it is difficult to makethem last. However, when providing the solution of sliding surfaces, thefriction can be reduced in different ways as known to the person skilledin the art.

The platform 6 comprises at least one elongated guide member 41extending laterally of the bogie 4, and the launch device 23correspondingly comprises at least one complementary guide beam 42extending along the length of the launch device 23 and slidably engagingwith the guide member 41 of the platform 6. The guide member 41 and theguide beam 42 are arc shaped. In this embodiment, the launch device 23comprises two such guide beams 42, distanced by the reception portion32. Each guide beam 42 comprises a bottom plate 53, having longitudinaledge portions 54, which protrude to the sides of the guide beam 42.Furthermore, the platform 6 comprises four such guide members 41, one ateach longitudinal side of the guide beams 42. Each guide member 41provides a groove 55 facing the guide beam 42. The edge portion 54extends into the groove 55.

The launch device 23 has at least one laterally elongated top surfaceportion 43, extending along the launch device 23. In this embodiment thelaunch device 23 comprises two such elongated top surface portions 43extending parallel to each other at a distance from each other, andconstituting top surfaces of the guide beams 42. Each end portion 11-14comprises two rollers 44 arranged at a distance from each other in thelongitudinal direction of the side beam 17, 18, and arranged to roll ontop of the respective top surface portions 43. This means that theweight of the load carrier is carried by the rollers at the end portions11-14 of the side beams 17, 18, i.e. at the connection portions 15, 16of the load carrier 2.

Furthermore, the launch device 23 comprises a retaining lip 45 extendingalong a longitudinal side edge of the launch device 23, and eachprotruding end portion 11-14 comprises a retaining member 46 protrudingunder the retaining lip 45 overlapping a portion of a bottom surface ofthe retaining lip 45. The retaining lip 45 is arranged at thelongitudinal side of the launch device 23 that is closest to the veryend of the railway wagon 1, and extends adjacent to one of the topsurfaces 43.

This retaining construction prevents the connection portion 16 of theload carrier 2 and the platform 6 from becoming vertically angledrelative to each other. Such an angled position could make it difficultto laterally displace the load carrier 2. The width of the retainingmember 46, i.e. its extension in the lateral direction of the railwaywagon, is but a small fraction of the length of the retaining lip 45. Ifa situation would occur where the retaining member 46 would exert alifting force, i.e. an upward force, on the retaining lip 45, and thuson the launch device 23, then the engagement between the guide elements41 and the edge portions 54 of the bottom plates 53 will keep the launchdevice 23 engaged with the platform 6.

Referring again to FIGS. 1 to 4, according to an embodiment of a methodof laterally displacing the load carrier 2, it is displaced as follows.This embodiment is described for the alternative of displacement, orlaunching, where one of the ends 7, 8 of the load carrier 2 isdisplaced, while there are several other alternatives as mentionedabove. Generally, the end 8 of the load carrier 2 is disconnected, andthe displacement device 22 is activated to displace the load carrier 2.In some greater detail, several reciprocating movements, each comprisinga feed stroke and a return stroke, are performed with the displacementdevice 22, until the end 8 of the load carrier 2 has been moved to aloading/unloading position beside the platform 6. For each reciprocatingmovement some operations are then performed, including the followingoperations.

The connection portion 16 of the load carrier 2 is connected with thelaunch device 23, by activating the launch device connection mechanism24 of each end portion 13, 14 comprised in the connection portion 16.More particularly, the piston 37 of the cylinder assembly 28 arranged atthe end portion 13 is driven into the aperture 38 of one of thereception members 33. Each platform connection mechanism 25 is activatedto disconnect. More particularly, at each end portion 13, 14 the screw35 of the engagement assembly 26 is retracted from the seat 27 of theshelf 49 such that the engagement between the screw 35 and the seat 27is released.

Then a first feed stroke is performed by means of the feeding device 29.The position shown in FIG. 1 has now been reached. The support device 30closest to the first side beam 13, which has now been moved outside ofthe platform 6, is lowered from its idle position to its supportposition in contact with the ground. In this position of the loadcarrier 2 the support device 30 is also beside the rails 50 of therailroad. Then, the platform connection mechanism 25 remaining withinthe width of the platform is activated to connection, i.e. the screw isdriven down into a corresponding seat 27 of the shelf 49, which is inposition, to clamp the shelf 49 again, and the connection portion 16 isdisconnected from the launch device 23 A return stroke is then performedby the feeding device 29. Due to the clamping of the shelf 49 the riskof pulling back the carrier 2 is eliminated. During this return strokethe rollers 44 of the first end portion 13 rolls off the top surfaceportion 43 of the launch device 23 and the rollers 44 of the second endportion 14 rolls along the top surface portion 43. Simultaneously, theretaining member 46 of the end portion 13 that is first leaving theplatform 6 is displaced from the retaining lip 45.

A second reciprocating movement is then performed. This includesreconnecting the launch device connection mechanism 24 of the second endportion 14, such that the load carrier 2 is again interconnected withthe launch device 23, releasing the platform connection mechanism 25,and driving the feeding device 29 through a second feed stroke to againmove the launch device 23 laterally of the platform 6 in the samedirection as during the first feed stroke, thereby further laterallydisplacing the load carrier 2. Then the launch device connectionmechanism 24 is switched again to be disconnected, etc., and a secondreturn stroke is performed.

A third feed stroke, and a third return stroke are performed in asimilar way. During a fourth feed stroke the second end portion 14 toois moved to a position beside the platform 6, the second support device31 is lowered to the ground and the launch device 23 is returned to itsoriginal position, as shown in FIG. 3. The ramp 21 is then lowered tothe ground and the truck 9 is driven on board the railway wagon 1, asshown in FIG. 4.

After the loading, the load carrier 2 is returned to the drive positionin a converse manner. When the launch device 23 is driven out tore-engage with the rollers 44 of each end portion 13, 14, the rollers 44are advantageous. In addition, the top surface portion 43 may bedesigned to slope at its end, further enhancing that operation.

It should be noted that depending on the structure of the feedingdevice, the launching operation may contain both more and fewer strokesthan four.

The method of displacing the load carrier 2 is useful for replacing theload carrier 2 with another one. The operations of the method are simplyperformed at both ends of the railway wagon 1 at the same time. Thisresults in a parallel displacement of the load carrier 2 to a positionwhere it is fully disconnected from the bogies 3, 4. All that remains isto disconnect tubes and cables which extend along the railway wagon fromone bogie 3 via the load carrier to the other bogie 4. The load carrier2 is then transported away and another load carrier is positioned forbeing connected to the bogies 3, 4, i.e. to the platforms 5, 6 andlaunch devices of the bogies 3, 4. This replacement of load carriers canbe done for any applicable purpose, for instance to perform repairs ormaintenance, or to change the length of the load carrier. In the lattercase, one of the bogies 3, 4 will have to be moved along the railway toadapt the distance between the bogies to the length of the load carrier.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive; theinvention is not limited to the disclosed embodiments.

For example, the feeding device can be of another kind such as a rollerscrew.

Other variations to the disclosed embodiments can be understood andeffected by those skilled in the art in practicing the claimedinvention, from a study of the drawings, the disclosure, and theappended claims. In the claims, the word “comprising” does not excludeother elements or steps, and the indefinite article “a” or “an” does notexclude a plurality. The mere fact that certain measures are recited inmutually different dependent claims does not indicate that a combinationof these measured cannot be used to advantage. Any reference signs inthe claims should not be construed as limiting the scope.

1. A railway wagon, comprising: a load carrier; front and rear bogies,wherein each bogie comprises a platform, which is rotatably mounted,wherein the load carrier is releasably connected to the respectiveplatforms, and laterally displaceable in relation to the respectiveplatforms, the load carrier having a front end and a rear end and beingat each end provided with a connection portion; two support devices,which are laterally spaced, and which support the load carrier in aposition where it is laterally displaced in relation to the platform,the support devices being vertically operable between an idle positionand a support position, in which the support devices abut against theground; and, a displacement device for laterally displacing the loadcarrier, wherein the displacement device comprises: a reciprocatinglaunch device, which is arranged to reciprocate laterally of theplatform, a launch device connection mechanism for releasably connectingthe connection portion with the launch device, and a platform connectionmechanism for releasably connecting the connection portion with theplatform.
 2. The railway wagon according to claim 1, wherein the launchdevice is elongated and extends laterally of the platform, wherein thedisplacement device further comprises a reciprocating feeding deviceattached to the launch device and to the platform, wherein the launchdevice is movable, by means of the feeding device, between an idleposition, and a laterally displaced position.
 3. The railway wagonaccording to claim 2, wherein the feeding device is a cylinder assembly.4. The railway wagon according to claim 2, wherein the launch deviceconnection mechanism comprises a reciprocating engagement elementarranged at the connection portion, and a reception portion at thelaunch device, wherein the engagement element is reciprocatingly movableto respectively engage with and disengage from the reception portion. 5.The railway wagon according to claim 4, wherein the reception portioncomprises several reception members distributed along the length of thelaunch device.
 6. The railway wagon according to claim 4, wherein theengagement element is a cylinder assembly, and each reception membercomprises an aperture arranged to receive a piston of the cylinderassembly.
 7. The railway wagon according to claim 1, wherein theplatform connection mechanism comprises an engagement assembly arrangedat the connection portion, and a seat arranged at the platform andadapted to receive a piston comprised in the engagement assembly toconnect the load carrier with the platform.
 8. The railway wagonaccording to claim 1, wherein the platform comprises a support surface,which supports the launch device.
 9. The railway wagon according toclaim 1, wherein the platform comprises an elongated guide memberextending laterally of the bogie, and the launch device comprises aguide beam extending along the length of the launch device and slidablyengaging with the guide member of the platform, wherein the guide memberand the guide beam are arc shaped.
 10. The railway wagon according toclaim 1, wherein the load carrier comprises opposite side beams, whereineach side beam comprises a protruding end portion at each end thereof,and wherein the connection portion comprises the protruding end portionsof the side beams.
 11. The railway wagon according to claim 10, whereinthe launch device is provided with a laterally elongated top surfaceportion, and wherein each protruding end portion is provided with aroller arranged to roll on top of the top surface portion.
 12. Therailway wagon according to claim 10, wherein the launch device comprisesa retaining lip extending along a side edge of the launch device, andwherein each protruding end portion comprises a retaining memberprotruding under the retaining lip overlapping a portion of a bottomsurface of the retaining lip.
 13. A method of laterally displacing aload carrier of a railway wagon, the method comprising: displacing atleast one of the ends of the load carrier by performing at least onereciprocating movement, comprising a feed stroke and a return stroke,with the displacement device, until the end of the load carrier has beenmoved to a loading/unloading position beside the bogie, comprising:connecting the connection portion, if disconnected, with the launchdevice; disconnecting, if connected, the connection portion from theplatform; performing a feed stroke by moving the launch device laterallyfrom an idle position to a laterally displaced position; lowering afirst support device of said support devices to the support position;disconnecting the connection portion from the launch device; performinga return stroke moving the launch device back to its idle position;connecting the connection portion with the launch device and performinganother feed stroke; and lowering the second support device to thesupport position.
 14. A method of exchanging a load carrier of a railwaywagon comprising: applying the method of claim 13 for simultaneouslydisplacing both ends of the load carrier; disconnecting connections,tubes and cables at both ends of the load carrier from the bogies;removing the load carrier and providing a replacement load carrier; andassembling the replacement load carrier with the bogies by reversing theoperations of the method of claim 13 and connecting connections, tubesand cables.